JP2014124628A - Catalyst for c2 oxygen compound synthesis, apparatus and method for producing c2 oxygen compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a catalyst for C2 oxygen compound synthesis, with which a proportion of ethanol in a C2 oxygen compound being a product material can be increased and consequently the ethanol can be efficiently synthesized.SOLUTION: The catalyst for C2 oxygen compound synthesis enables a C2 oxygen compound to be synthesized from a gaseous mixture including hydrogen and carbon monoxide. The catalyst contains: (A) a component of one or more kinds of elements selected from a group consisting of elements belonging to the groups 7-12 of the periodic table, (B) a component of alkali metal; (C) a component of one or more kinds elements selected from a group consisting of elements belonging to the group 2 of the periodic table; and (D) a component of one or more kinds of elements selected from a group consisting of elements belonging to the groups 5-6 of the periodic table.

Description

  The present invention relates to a catalyst for synthesizing C2 oxygenates, an apparatus for producing C2 oxygenates, and a method for producing C2 oxygenates.

Bioethanol is being popularized as an alternative fuel for petroleum. Bioethanol is mainly produced by saccharification and fermentation of sugarcane and corn. In recent years, techniques for producing bioethanol from woody and herbaceous biomass (also referred to as cellulose biomass) such as waste wood and unused parts of crops such as rice straw that do not compete with food and feed have been developed.
In order to produce bioethanol using cellulose-based biomass as a raw material using a conventional ethanol fermentation method, it is necessary to saccharify cellulose. As saccharification methods, there are concentrated sulfuric acid saccharification method, dilute sulfuric acid / enzymatic saccharification method, hydrothermal saccharification method and the like, but many problems still remain to produce bioethanol at low cost.

On the other hand, there is a method of synthesizing ethanol from this mixed gas after converting cellulosic biomass into a mixed gas containing hydrogen and carbon monoxide. By this method, the trial which manufactures bioethanol efficiently from the cellulose biomass which is difficult to apply the ethanol fermentation method is made. In addition, according to this method, not only woody and herbaceous biomass but also various biomass such as animal biomass derived from animal carcasses and feces, raw garbage, waste paper, and waste fiber can be used as a raw material.
Furthermore, since a mixed gas of hydrogen and carbon monoxide can be obtained from resources other than petroleum such as natural gas and coal, the method of synthesizing oxygenates from the mixed gas has been studied as a technology to escape from dependence on petroleum. Yes.
Examples of a method for obtaining C2 oxygenates such as ethanol, acetaldehyde, and acetic acid from a mixed gas of hydrogen and carbon monoxide include a method in which a mixed gas is brought into contact with a catalyst in which rhodium and an alkali metal are supported on a silica gel carrier. Known (for example, Patent Documents 1 and 2).

Japanese Patent Publication No. 61-36730 Japanese Patent Publication No. 61-36731

However, conventional catalysts for synthesizing C2 oxygenates have a problem that a large amount of C2 oxygenates other than ethanol are produced, and much time and energy are required for the step of isolating ethanol.
Therefore, the present invention is directed to a catalyst for synthesizing C2 oxygenates that can efficiently synthesize ethanol by increasing the ratio of ethanol in the product C2 oxygenates.

The catalyst for synthesizing C2 oxygenates according to the present invention is a catalyst for synthesizing C2 oxygenates from a mixed gas containing hydrogen and carbon monoxide, and is a catalyst for synthesizing C2 oxygenates. One or more selected from the group consisting of elements belonging to the group; and (B) component: alkali metal; and (C) component: one or more selected from the group consisting of elements belonging to Group 2 of the periodic table; (D) component: 1 or more types selected from the group which consists of an element which belongs to the 5th-6th group of a periodic table, It is characterized by the above-mentioned.
The component (A) preferably contains at least rhodium and manganese, and the component (C) preferably contains at least magnesium.

  An apparatus for producing a C2 oxygenate of the present invention comprises a reaction tube filled with the catalyst for synthesizing the C2 oxygenate of the present invention, a supply means for supplying the mixed gas into the reaction tube, and generated from the reaction tube And a discharge means for discharging the object.

  The method for producing a C2 oxygenate according to the present invention is characterized in that a mixed gas containing hydrogen and carbon monoxide is brought into contact with the catalyst for synthesizing a C2 oxygenate according to the present invention to obtain a C2 oxygenate.

  According to the catalyst for synthesizing C2 oxygenates of the present invention, ethanol can be efficiently synthesized by increasing the ratio of ethanol in the product C2 oxygenate.

  In this article, oxygenates include alcohols such as methanol, ethanol, and propanol, carboxylic acids such as acetic acid, aldehydes such as acetaldehyde, esters such as methyl formate, ethyl formate, methyl acetate, and ethyl acetate, carbon atoms, hydrogen atoms, and oxygen atoms. Means a molecule consisting of Among oxygenates, compounds having 2 carbon atoms (for example, acetic acid, ethanol, acetaldehyde, etc.) are referred to as C2 oxygenates.

It is a schematic diagram of the manufacturing apparatus of the C2 oxygenate concerning one Embodiment of this invention.

(Catalyst for C2 oxygenate synthesis)
The catalyst for synthesizing C2 oxygenates of the present invention (hereinafter sometimes simply referred to as catalyst) is (A) component: one or more selected from the group consisting of elements belonging to Groups 7 to 12 of the periodic table; (B) component: alkali metal, (C) component: one or more selected from the group consisting of elements belonging to Group 2 of the periodic table, and (D) component: belonging to Groups 5-6 of the periodic table One or more selected from the group consisting of elements. The catalyst contains the components (A) to (D) (hereinafter, the components (A) to (D) may be collectively referred to as catalyst metals), thereby increasing the selectivity of ethanol and the product C2 The ratio of ethanol in oxygenates can be increased.

In this article, “selectivity” is the percentage of the number of moles of CO consumed in the gas mixture that is occupied by the number of moles of C converted to a specific oxygenate. For example, according to the following formula (α), the selectivity for ethanol as the C2 oxygenate is 100 mol%. On the other hand, according to the following formula (β), the selectivity for ethanol as a C2 oxygenate is 50 mol%, and the selectivity for acetaldehyde as a C2 oxygenate is also 50 mol%.
4H ₂ + 2CO → CH ₃ CH ₂ OH + H ₂ O (α)
7H ₂ + 4CO → C ₂ H ₅ OH + CH ₃ CHO + 2H ₂ O (β)

The component (A) is at least one selected from the group consisting of elements belonging to Groups 7 to 12 of the periodic table. By containing the component (A), the catalyst can convert carbon monoxide into C2 oxygenate.
As the component (A), manganese (Mn), ruthenium (Ru), rhodium (Rh), and zinc (Zn) are preferable, manganese and rhodium are more preferable, and a combination of manganese and rhodium is more preferable. By using these components (A), the selectivity of ethanol can be further increased.

  (B) A component is an alkali metal. Examples of the component (B) include lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), etc. Among them, reducing by-products and increasing CO conversion rate, From the viewpoint of more efficiently synthesizing the C2 oxygenate, lithium is preferable. The “CO conversion rate” means “percentage occupied by the number of moles of consumed CO in the number of moles of CO in the mixed gas”.

  The component (C) is at least one selected from the group consisting of elements belonging to Group 2 of the periodic table. By containing the component (C), the catalyst can further improve the selectivity of ethanol. Among the components (C), magnesium (Mg) is preferable from the viewpoint of further increasing the selectivity of ethanol.

(D) A component is 1 or more types selected from the group which consists of an element which belongs to the 5th-6th group of a periodic table. A catalyst can raise the selectivity of ethanol by containing (D) component. As the component (D), vanadium (V) and tungsten (W) are preferable and vanadium is more preferable from the viewpoint of further improving the selectivity of ethanol.
In addition, when at least rhodium is contained as the component (A), vanadium is preferably used as the component (D). Rhodium and vanadium have a strong interaction due to their high ionic valence, and promote CO insertion and dissociation reactions that occur in the vicinity of these junction interfaces. For this reason, in the synthesis reaction of C2 oxygenates, it is considered that carbon monoxide easily proceeds to ethanol without stopping to aldehyde or acetic acid.

The catalyst of the present invention preferably has a composition represented by the following formula (I), that is, a composition having both rhodium and manganese as the component (A).
rRh / mMn / bB / cC / dD (I)
[In the formula (I), B represents the component (B), C represents the component (C), and D represents the component (D). r, m, b, c, d represents a molar ratio relative to 1 mole of rhodium;
r = 1,
m = 0.075-7.5,
b = 0.0275-2.75,
c = 0.0143-1.43
d = 0.1-10. ]

In formula (I), if m is less than the above lower limit value, the manganese content is too small and the ethanol selectivity may not be sufficiently increased, and if it exceeds the above upper limit content of other metals. However, the ethanol selectivity may not be sufficiently increased.
In the formula (I), when b is less than the lower limit, the content of the component (B) is too small and the CO conversion rate may not be sufficiently increased. There is a possibility that the content is too small and the selectivity of ethanol cannot be sufficiently increased.
In formula (I), if c is less than the above lower limit, the content of component (C) is too small, and the ethanol selectivity may not be sufficiently increased. Therefore, the ethanol selectivity may not be sufficiently increased.
In formula (I), if d is less than the above lower limit value, the content of component (D) is too small and the ethanol selectivity may not be sufficiently increased. Therefore, the ethanol selectivity may not be sufficiently increased.

 The catalyst may be an aggregate of catalytic metals, or a supported catalyst in which the catalytic metal is supported on a carrier, and among these, a supported catalyst is preferable. By using the supported catalyst, the contact efficiency between the catalyst metal and the mixed gas can be increased, and the selectivity of ethanol can be further improved.

As the carrier, a carrier conventionally used for a catalyst can be used. For example, a porous carrier is preferable.
The material of the porous carrier is not particularly limited, and examples thereof include silica, zirconia, titania, magnesia, alumina, activated carbon, zeolite, etc. Among them, various products having different specific surface areas and pore diameters can be procured on the market. Therefore, silica is preferable.

The size of the porous carrier is not particularly limited. For example, a porous carrier made of silica preferably has a particle size of 0.5 to 5000 μm. The particle size of the porous carrier is adjusted by sieving.
In addition, the porous carrier preferably has a narrowest particle size distribution.

The total pore volume (total pore volume) in the porous carrier is not particularly limited, but is preferably 0.01 to 1.0 mL / g, more preferably 0.1 to 0.8 mL / g, 0 More preferably, it is 3 to 0.7 mL / g. If the total pore volume is less than the above lower limit, the specific surface area of the porous carrier becomes insufficient, the amount of catalyst metal supported becomes insufficient, and the CO conversion rate may be lowered. If the total pore volume exceeds the above upper limit value, the diffusion rate of the mixed gas as the raw material becomes too fast, the contact time between the catalyst metal and the mixed gas becomes insufficient, and the ethanol selectivity may be lowered. is there.
The total pore volume is a value measured by a water titration method. The water titration method is a method in which water molecules are adsorbed on the surface of a porous carrier and the pore distribution is measured from the condensation of the molecules.

The average pore diameter of the porous carrier is not particularly limited, but is preferably, for example, 2 to 20 nm, more preferably more than 5 nm and less than 14 nm, further preferably more than 5 nm and not more than 10 nm. If the average pore diameter is less than the above lower limit, the amount of catalyst metal supported is reduced, and the CO conversion rate may be reduced. If the average pore diameter exceeds the above upper limit value, the diffusion rate of the mixed gas becomes too fast, the contact time between the catalyst metal and the mixed gas becomes insufficient, and the ethanol selectivity may be lowered.
In addition, if the average pore diameter is not more than the above upper limit, the specific surface area of the porous carrier is sufficiently large, the heat transfer efficiency to the catalyst is increased, and the C2 oxygenate can be synthesized more efficiently.
The average pore diameter is a value measured by the following method. When the average pore diameter is 0.1 nm or more and less than 10 nm, it is calculated from the total pore volume and the BET specific surface area. When the average pore diameter is 10 nm or more, it is measured by a mercury porosimetry porosimeter.
Here, the BET specific surface area is a value calculated from the amount of adsorption and the pressure at that time, using nitrogen as the adsorption gas.
In the mercury intrusion method, mercury is pressurized and pressed into the pores of the porous carrier, and the average pore diameter is calculated from the pressure and the amount of mercury inserted.

Although the specific surface area of a porous support | carrier is not specifically limited, For example, 1-1000 m < ² > / g is preferable, 300-800 m < ² > / g is more preferable, 400-700 m < ² > / g is more preferable. If the specific surface area is not less than the above lower limit, the amount of catalyst metal supported is sufficient, and the CO conversion can be further increased. In addition, if the specific surface area is not less than the lower limit, the yield of C2 oxygenates can be further increased. This is presumably because the use of a porous support having a large specific surface area increases the efficiency of heat transfer to the catalyst and further promotes the synthesis reaction of C2 oxygenates.
If the specific surface area is not more than the above upper limit value, the diffusion rate of the mixed gas becomes more appropriate, and the ethanol selectivity can be further increased.
The specific surface area is a BET specific surface area measured by a BET gas adsorption method using nitrogen as an adsorption gas.

 The supported state of the catalyst metal in the supported catalyst is not particularly limited. For example, a powdered metal may be supported on the porous support, or may be supported on the porous support in the form of a metal element. The state may be sufficient, and among these, the state of being supported on the porous carrier in the form of a metal element is preferable. If it is in a state of being supported on the porous carrier in the form of a metal element, the contact area with the mixed gas is increased, and the CO conversion rate can be further increased.

 The amount of the catalyst metal supported in the supported catalyst is determined in consideration of the type of the catalyst metal, the type of the porous carrier, and the like. For example, if the porous carrier is silica, it is 0 with respect to 100 parts by mass of the porous carrier. 0.05 to 30 parts by mass is preferable, and 1 to 10 parts by mass is more preferable. If the amount is less than the above lower limit value, the amount of the catalyst metal is too small and the CO conversion rate may decrease, and if the value exceeds the upper limit value, the catalyst metal cannot be uniformly and highly dispersed, and the ethanol selectivity decreases. Or the CO conversion may be reduced.

The catalyst of this invention is manufactured according to the manufacturing method of a conventionally well-known metal catalyst. Examples of the method for producing the catalyst include an impregnation method, an immersion method, an ion exchange method, a coprecipitation method, a kneading method, and the like. Among these, the impregnation method is preferable. By using the impregnation method, in the obtained catalyst, the components (A) to (D) are more uniformly dispersed, the contact efficiency with the mixed gas is further increased, and the C2 oxygenate can be synthesized more efficiently.
The raw material compounds of the components (A) to (D) used for the catalyst production include oxides, chlorides, nitrates, carbonates and other inorganic salts, oxalates, acetylacetonate salts, dimethylglyoxime salts, ethylenediamineacetic acid Organic compounds such as salts or chelate compounds, carbonyl compounds, cyclopentadienyl compounds, ammine complexes, alkoxide compounds, alkyl compounds, etc., used when producing various catalysts as compounds of components (A) to (D) Is mentioned.

The impregnation method will be described. First, the raw material compounds of the components (A) to (D) are dissolved in a solvent such as water, methanol, ethanol, tetrahydrofuran, dioxane, hexane, benzene, toluene, and the carrier is immersed in the obtained solution (impregnation liquid). Then, the carrier is impregnated with the impregnation liquid. When a porous material is used as the carrier, the impregnating solution is sufficiently permeated into the pores of the carrier, and then the solvent is evaporated to form a catalyst.
As a method of impregnating the carrier with the impregnating solution, a method in which a solution in which all raw material compounds are dissolved is impregnated in the carrier (simultaneous method), a solution in which each raw material compound is separately dissolved is prepared, and each solution is sequentially added to the carrier. And the like (sequential method) and the like. Among these, the sequential method is preferable. The catalyst obtained by the sequential method can synthesize C2 oxygenates more efficiently, and can further improve the selectivity of ethanol.

  An example of the sequential method will be described. First, the support containing the component (C) (primary impregnation liquid) is impregnated in the support (primary impregnation step), and dried to obtain a primary support in which the component (C) is supported on the support (primary support step). Then, a method (secondary impregnation step) in which a solution containing the components (A) to (B) and (D) (secondary impregnation liquid) is impregnated in the primary support (secondary impregnation step) is dried (secondary support step). It is done. In this way, by supporting the component (C) on the carrier and then supporting the catalyst metal other than the component (C) on the carrier, the catalyst is more highly dispersed in the components (A) to (B) and (D). Therefore, C2 oxygenates can be synthesized more efficiently, and the selectivity of ethanol can be further improved.

Examples of the primary supporting step include a method of drying the carrier impregnated with the primary impregnating liquid (primary drying operation), and heating and baking it at an arbitrary temperature (primary baking operation).
The drying method in the primary drying operation is not particularly limited, and examples thereof include a method of heating the carrier impregnated with the primary impregnation liquid at an arbitrary temperature. The heating temperature in primary drying operation should just be the temperature which can evaporate the solvent of a primary impregnation liquid, and will be 80-120 degreeC, if a solvent is water. The heating temperature in the primary firing operation is, for example, 300 to 600 ° C. By performing the primary firing operation, components that do not contribute to the catalytic reaction among the components contained in the raw material compound of component (C) are sufficiently volatilized, and the catalytic activity can be further enhanced.

Examples of the secondary supporting step include a method of drying the primary support impregnated with the secondary impregnating liquid (secondary drying operation), and further heating and baking at an arbitrary temperature (secondary baking operation).
The drying method in the secondary drying operation is not particularly limited, and examples thereof include a method of heating the primary carrier impregnated with the secondary impregnation liquid at an arbitrary temperature. The heating temperature in secondary drying operation should just be the temperature which can evaporate the solvent of a secondary impregnation liquid, and will be 80-120 degreeC, if a solvent is water. The heating temperature in the secondary firing operation is, for example, 300 to 600 ° C. By performing the secondary firing operation, components that do not contribute to the catalytic reaction among the components contained in the raw material compound of the catalytic metal are sufficiently volatilized, and the catalytic activity can be further enhanced.

The catalyst produced by the above-described method is usually subjected to reduction treatment to be activated and used for the synthesis of C2 oxygenate. As the reduction treatment, a method of bringing a catalyst into contact with a gas containing hydrogen is simple and preferable. At this time, the treatment temperature may be a temperature at which rhodium is reduced, that is, about 100 ° C., but is preferably 200 to 600 ° C. In addition, for the purpose of sufficiently dispersing the components (A) to (D), hydrogen reduction may be performed while gradually or gradually increasing the temperature from a low temperature. For example, the catalyst may be subjected to a reduction treatment in the presence of carbon monoxide and water, or in the presence of a reducing agent such as hydrazine, a borohydride compound, or an aluminum hydride compound.
For example, the heating time in the reduction treatment is preferably 1 to 10 hours, and more preferably 2 to 5 hours. If it is less than the said lower limit, the reduction | restoration of (A)-(D) component becomes inadequate, and there exists a possibility that the manufacturing efficiency of C2 oxygenate may fall. Above the upper limit, the metal particles in the components (A) to (D) are aggregated, and the synthesis efficiency of the C2 oxygenate may be reduced, or the energy in the reduction treatment may be excessive, resulting in an economic disadvantage. There is.

(C2 oxygenated product production equipment)
An apparatus for producing a C2 oxygenate of the present invention (hereinafter sometimes referred to simply as a production apparatus) is produced from a reaction tube filled with the catalyst of the present invention, a supply means for supplying a mixed gas into the reaction tube, and the reaction tube. And a discharging means for discharging the object.

  An example of the manufacturing apparatus of the present invention will be described with reference to FIG. FIG. 1 is a schematic diagram showing a manufacturing apparatus 10 according to an embodiment of the present invention. The production apparatus 10 includes a reaction tube 1 filled with a catalyst to form a reaction bed 2, a supply tube 3 connected to the reaction tube 1, a discharge tube 4 connected to the reaction tube 1, and a reaction tube 1. The temperature control part 5 connected and the pressure control part 6 provided in the discharge pipe 4 are provided.

The reaction tube 1 is preferably made of a material inert to the mixed gas and the synthesized C2 oxygenate, and preferably has a shape capable of withstanding heating of about 100 to 500 ° C. or pressurization of about 10 MPa. An example of the reaction tube 1 is a substantially cylindrical member made of stainless steel.
The supply pipe 3 is a supply means for supplying the mixed gas into the reaction tube 1 and includes, for example, a pipe made of stainless steel or the like.
The discharge pipe 4 is a discharge means for discharging the synthesis gas (product) containing the C2 oxygenated product synthesized in the reaction bed 2 and includes, for example, a pipe made of stainless steel or the like.
The temperature control part 5 should just be what can make the reaction bed 2 in the reaction tube 1 arbitrary temperature, for example, an electric furnace etc. are mentioned.
The pressure control part 6 should just be what can make the pressure in the reaction tube 1 arbitrary pressure, for example, a well-known pressure valve etc. are mentioned.
The manufacturing apparatus 10 may include a known device such as a gas flow rate control unit that adjusts a gas flow rate such as mass flow.

(Method for producing C2 oxygenate)
In the method for producing a C2 oxygenate according to the present invention, a mixed gas is brought into contact with a catalyst. An example of the method for producing the C2 oxygenated product of the present invention will be described using the production apparatus of FIG.
First, the inside of the reaction tube 1 is set to an arbitrary temperature and an arbitrary pressure, and the mixed gas 20 is caused to flow into the reaction tube 1 from the supply tube 3.

The mixed gas 20 is not particularly limited as long as it contains hydrogen and carbon monoxide. For example, the mixed gas 20 may be prepared from natural gas or coal, biomass gas obtained by gasifying biomass, or the like. It may also be one obtained by gasifying organic waste such as waste plastic, waste paper, and waste clothing (hereinafter sometimes referred to as recycle gas). Biomass gas and recycle gas are obtained by a conventionally known method, for example, heating pulverized biomass or organic waste in the presence of water vapor (for example, 800 to 1000 ° C.).
When biomass gas or recycle gas is used as the mixed gas 20, the gas is used for the purpose of removing impurities such as tar, sulfur, nitrogen, chlorine and moisture before supplying the mixed gas 20 into the reaction tube 1. A purification treatment may be applied. As the gas purification treatment, for example, various methods known in the technical field such as a wet method and a dry method can be adopted. Examples of wet methods include sodium hydroxide method, ammonia absorption method, lime / gypsum method, magnesium hydroxide method, and dry methods include activated carbon adsorption method such as pressure swing adsorption (PSA) method, electron beam method, etc. Is mentioned.

The mixed gas 20 is mainly composed of hydrogen and carbon monoxide, that is, the total of hydrogen and carbon monoxide in the mixed gas 20 is preferably 50% by volume or more, and 80% by volume or more. More preferably, it is more preferable that it is 90 volume% or more, and 100 volume% may be sufficient. The greater the content of hydrogen and carbon monoxide, the higher the amount of C2 oxygenate produced and the more efficiently ethanol can be produced.
The volume ratio represented by hydrogen / carbon monoxide in the mixed gas 20 (hereinafter sometimes referred to as H ₂ / CO ratio) is preferably 1/5 to 5/1, and more preferably 1/2 to 3/1. 1/1 to 2.5 / 1 is more preferable. If it is in the said range, C2 oxygenate can be manufactured more efficiently.
The mixed gas 20 may contain methane, ethane, ethylene, nitrogen, carbon dioxide, water, etc. in addition to hydrogen and carbon monoxide.

  The temperature (reaction temperature) at which the mixed gas 20 is brought into contact with the catalyst, that is, the temperature in the reaction tube 1 is, for example, preferably 150 to 450 ° C, more preferably 200 to 400 ° C, and further preferably 250 to 350 ° C. . If it is more than the said lower limit, the speed | rate of a catalytic reaction can fully be raised and ethanol can be manufactured more efficiently. If it is below the above upper limit, the ethanol synthesis reaction is the main reaction, and the ethanol selectivity can be further improved.

  The pressure (reaction pressure) at the time of bringing the mixed gas 20 and the catalyst into contact, that is, the pressure in the reaction tube 1, for example, is preferably 0.5 to 10 MPa, more preferably 1 to 7.5 MPa, and further preferably 2 to 5 MPa. preferable. If it is more than the said lower limit, the speed | rate of a catalytic reaction can fully be raised and C2 oxygenate can be manufactured more efficiently. If it is below the above upper limit, the ethanol synthesis reaction is the main reaction, and the ethanol selectivity can be further improved.

The inflowing mixed gas 20 flows while in contact with the catalyst in the reaction bed 2, and a part thereof becomes C2 oxygenated product.
While the mixed gas 20 flows through the reaction bed 2, for example, a C2 oxygenate is generated by a catalytic reaction represented by the following formulas (1) to (5).
3H ₂ + 2CO → CH ₃ CHO + H ₂ O (1)
4H ₂ + 2CO → CH ₃ CH ₂ OH + H ₂ O (2)
H ₂ + CH ₃ CHO → CH ₃ CH ₂ OH (3)
2H ₂ + 2CO → CH ₃ COOH (4)
2H ₂ + CH ₃ COOH → CH ₃ CH ₂ OH + H ₂ O (5)

  Then, the synthesis gas 22 containing this C2 oxygenate is discharged from the discharge pipe 4. The synthesis gas 22 is not particularly limited as long as it contains ethanol, but may contain C2 oxygenates such as acetic acid and acetaldehyde and other oxygenates in addition to ethanol.

  As for the supply speed of the mixed gas 20, for example, the space velocity of the mixed gas in the reaction bed 2 (the value obtained by dividing the supply amount of gas per unit time by the catalyst amount (volume conversion)) is preferably 10 to 10 100000 L / L-catalyst / h, more preferably 1000 to 50000 L / L-catalyst / h, still more preferably 3000 to 20000 L / L-catalyst / h. The space velocity is appropriately adjusted in consideration of the reaction pressure, the reaction temperature, and the composition of the mixed gas that is a raw material.

  If necessary, the synthesis gas 22 discharged from the discharge pipe 4 may be treated with a gas-liquid separator or the like to separate ethanol from unreacted mixed gas 20 or oxygenated products other than ethanol.

  In the present embodiment, the mixed gas is brought into contact with the reaction bed 2 of the fixed bed. However, for example, the catalyst may be in a form other than the fixed bed, such as a fluidized bed or a moving bed, and the mixed gas may be brought into contact therewith.

In the present invention, the obtained oxygenates may be separated for each necessary component by distillation or the like.
In the present invention, a product other than ethanol (for example, acetic acid, acetaldehyde, etc., C2 oxygenates other than ethanol or esters such as ethyl acetate, methyl acetate, methyl formate) is hydrogenated and converted to alcohol (alcohol Process) may be provided. Examples of the alcoholation step include a method in which an oxygenate containing acetaldehyde, acetic acid and the like is brought into contact with a hydrogenation catalyst and converted to ethanol.
Here, as the hydrogenation catalyst, a catalyst known in the art can be used, and copper, copper-zinc, copper-chromium, copper-zinc-chromium, iron, rhodium-iron, rhodium-molybdenum, palladium, palladium- Examples thereof include iron, palladium-molybdenum, iridium-iron, rhodium-iridium-iron, iridium-molybdenum, rhenium-zinc, platinum, nickel, cobalt, ruthenium, rhodium oxide, palladium oxide, platinum oxide, and ruthenium oxide. These hydrogenation catalysts may be supported catalysts supported on the same support as the support used in the catalyst of the present invention, and as the supported catalyst, copper, copper-zinc, copper-chromium or copper-zinc- A copper-based catalyst in which chromium is supported on a silica-based carrier is preferable. As a method for producing a hydrogenation catalyst which is a supported catalyst, a simultaneous method or a sequential method may be used as in the catalyst of the present invention.

  As described above, by using the catalyst of the present invention, it is possible to efficiently synthesize ethanol from a mixed gas by increasing the amount of ethanol in the C2 oxygenate.

  EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to the examples.

(Examples 1-4)
1.23 g of an aqueous solution (primary impregnating solution) containing 0.0148 g of magnesium chloride hexahydrate (MgCl ₂ .6H ₂ O) was added to a porous carrier (material: silica, particle size: 1.18 to 2.36 mm, average) Pore diameter: 5.7 nm, total pore volume: 0.61 mL / g, specific surface area: 430 m ² / g) was dropped into 2.0 g and impregnated (primary impregnation step). This was dried at 110 ° C. for 3 hours (primary drying operation), and further fired at 600 ° C. for 4.5 hours to obtain a primary support (primary firing operation, primary support step). Rhodium chloride trihydrate (RhCl ₃ .3H ₂ O) 0.1535 g, manganese chloride dihydrate (MnCl ₂ .2H ₂ O) 0.0865 g, lithium chloride monohydrate (LiCl · H ₂ O) ) 1.48 g of an aqueous solution (secondary impregnating solution) containing 0.0097 g and 0.0115 g of vanadium chloride (VCl ₃ ) is dropped on the primary carrier to be impregnated (secondary impregnation step). The catalyst was obtained by drying for a period of time (secondary drying operation) and further calcining at 400 ° C. for 4.5 hours (secondary calcining operation, secondary support step). In the total of the primary impregnating liquid and the secondary impregnating liquid, the molar ratio of the catalyst metal is rhodium: magnesium = 1: 0.125, rhodium: manganese = 1: 0.75, rhodium: lithium = 1: 0.275, Rhodium: vanadium = 1: 1.

1 g of the catalyst obtained in each example was filled into a stainless steel cylindrical reaction tube having a diameter of 0.5 inch (1.27 cm) and a length of 10 inches (25.4 cm) to form a reaction bed. A production apparatus similar to the production apparatus for C2 oxygenates was obtained.
The catalyst was subjected to reduction treatment by heating at 320 ° C. for 2.5 hours while flowing hydrogen gas at 30 mL / min at normal pressure through the reaction bed.
The reaction bed was set to 250 ° C., the reaction bed was set to the reaction temperature shown in Table 1, and the mixed gas (H ₂ / CO ratio = 2/1) was introduced into the reaction bed at a space velocity of 14400 L / L-catalyst / h and 2 MPa. The C2 oxygenate was produced by distribution.
The mixed gas was passed through the reaction bed for 3 hours, and the resultant synthesis gas was recovered and analyzed by gas chromatography.
The selectivity (mol%) of each product and the ethanol ratio (mol%) in the C2 oxygenate were calculated from the obtained data. The results are shown in Table 1. In the table, the ratio of ethanol in the C2 oxygenate was calculated as the content ratio of ethanol in the total amount of ethanol, acetaldehyde and acetic acid in the product.

(Comparative Examples 1-2)
A C2 oxygenate was produced in the same manner as in Example 1 except that the catalyst was replaced with the catalyst obtained by the following production method. The selectivity (mol%) of each product and the ethanol ratio in the C2 oxygenate (Mole%) was calculated, and these results are shown in Table 1.

<Method for producing catalyst>
In the secondary impregnation step, 0.154 g of rhodium chloride trihydrate (RhCl ₃ .3H ₂ O), 0.0865 g of manganese chloride dihydrate (MnCl ₂ .2H ₂ O), and lithium chloride monohydrate A catalyst was obtained in the same manner as in Example 1 except that 1.47 g of an aqueous solution (secondary impregnation liquid) containing 0.0097 g of (LiCl · H ₂ O) was impregnated. In the total of the primary impregnating liquid and the secondary impregnating liquid, the molar ratio of the catalyst metal is rhodium: magnesium = 1: 0.125, rhodium: manganese = 1: 0.75, rhodium: lithium = 1: 0.275. is there.

As shown in Table 1, in Examples 1 to 4 to which the present invention was applied, the ethanol selectivity was 35.1 mol% or more, and the ethanol ratio in the C2 oxygenate was 88.7 mol% or more. It was.
On the other hand, Comparative Examples 1 and 2 not containing vanadium had an ethanol selectivity of 20.6 mol% or less and an ethanol ratio in the C2 oxygenate of 53.7 mol% or less.
From this result, it was found that by applying the present invention, ethanol can be efficiently synthesized from a mixed gas.

DESCRIPTION OF SYMBOLS 1 Reaction tube 2 Reaction bed 3 Supply tube 4 Discharge tube 5 Temperature control part 6 Pressure control part 10 Manufacturing apparatus 20 Mixed gas 22 Syngas

Claims (4)

In a catalyst for synthesizing C2 oxygenate that synthesizes C2 oxygenate from a mixed gas containing hydrogen and carbon monoxide,
(A) component: one or more selected from the group consisting of elements belonging to Groups 7-12 of the periodic table;
(B) component: alkali metal,
(C) component: one or more selected from the group consisting of elements belonging to Group 2 of the periodic table;
(D) component: one or more selected from the group consisting of elements belonging to Groups 5 to 6 of the periodic table;
A catalyst for synthesizing C2 oxygenates.   The catalyst for synthesizing C2 oxygenates according to claim 1, wherein the component (A) contains at least rhodium and manganese, and the component (C) contains at least magnesium.   A reaction tube filled with the catalyst for synthesizing C2 oxygenates according to claim 1, a supply unit that supplies the mixed gas into the reaction tube, and a discharge unit that discharges a product from the reaction tube. An apparatus for producing C2 oxygenates, comprising: A method for producing a C2 oxygenate, wherein the catalyst for synthesizing a C2 oxygenate according to claim 1 or 2 is brought into contact with a mixed gas containing hydrogen and carbon monoxide to obtain a C2 oxygenate.

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